Smart cards are thin, with a thickness no more than about 1 mm, and have generally rectangular upper and lower faces. One corner generally has a cut-away at a 45xc2x0 angle to polarize the card so it cannot be fully inserted in an upside-down orientation. One of the card faces is an active face that has contact pads that connect to an integrated circuit embedded in the card. Information is read into and out of the card by a card connector that includes an insulative support with contacts mounted on the support that engage the contact pads of a fully inserted card. As shown in our earlier U.S. Pat. No. 5,823,828, a sheet metal cover can have an upper portion that lies over the support upper face to form a card-receiving cavity between them. The sheet metal cover can have opposite sides that are bent around and under sides of the support to form a lower cover portion that holds the cover in place.
It is desirable to provide a mechanism that can be operated from the rear end of the connector, to partially eject a card that has been fully forwardly inserted. The mechanism can move the card rearwardly by a plurality of millimeters so a person can grasp the rear end of the card and pull it out. It is desirable to make the smart card connector so it is of minimum size and can be manufactured at minimum cost. A particular connector can be constructed to connect to a smart card of a particular size, it being noted that there are smart cards of different sizes in wide use. It is desirable to enable connection to smart cards of different types which have different dimensions and contact pad arrangements, or to connect to two or more smart cards simultaneously.
In accordance with one embodiment of the present invention, a connector is provided for use with a smart card, where the connector is of small size and low cost. The connector includes an insulative support with an upper face that lies adjacent to an active face of a smart card, with contacts mounted on the support to engage the contact pads on the active face. A sheet metal cover includes an upper portion that lies over the support upper face to form a cavity front portion between them, into which a smart card can be forwardly inserted to a fully inserted position. The sheet metal cover also includes sides that extend down along opposite sides of the support and a lower portion that form flanges lying under the support. The upper and lower sheet metal portions extend rearward of the support to form a rear cavity portion that is at least about as long as the front cavity portion.
An ejecting mechanism includes a lever pivotally mounted on the support and a sheet metal pusher that has upper and lower portions that straddle a side of the cover and that can be pushed forwardly to pivot the lever and eject the card a plurality of millimeters so the card can be pulled out.
The card has a polarizing cutout at one of its forward corners, which assures that the card will not be inserted upside-down. The vertical pivot axis of the ejection lever lies forward of the front edge of the fully inserted card, and lies in the polarizing corner cutout region. This reduces the length and width of the connector.
The upper and lower cover portions have rear ends that form card leadins that guide the card into a cavity. The cover upper portion has a rear end with an upper leadin part extending at a rearward-upper incline, while the cover lower portion has a rear end with lower leadin parts extending at rearward-downward inclines.
Two or more connectors can be stacked one on another to form a stack of connectors that each can receive a smart card. The contacts of each connector have tails that extend to traces on a circuit board to which they are soldered. In one type of stack, the tails of a lower connector extend from the rear edge of the support down to the circuit board, while the tails of an upper connector extend from the front edge of its support down to the circuit board. Slots in the sheet metal upper portions of each connector enable direct observance of solder connections. The rear portions of the covers are deformed to form loops at sides of one connector that receive prongs extending from the other connector.
In a stack where corresponding tails of each contact are connected to the same traces on the circuit board, the tails of the lower contacts forms loops that extend at least partially around the tails of the upper contacts to connect to them.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.